Klingon physiology makes them considerably tougher than humans; many of their major organs have redundancies that allow them to survive injuries that would kill a human. Klingons tend to be physically stronger than humans, but this is probably more a result of widespread martial training than a genetic trait. Klingons have a reputation for violence that is widely considered genetic, although it is just as likely a result of the [[monolithic culture|culture of militarism]] that has become dominant in Klingon society.

Klingon physiology makes them considerably tougher than humans; many of their major organs have redundancies that allow them to survive injuries that would kill a human. Klingons tend to be physically stronger than humans, but this is probably more a result of widespread martial training than a genetic trait. Klingons have a reputation for violence that is widely considered genetic, although it is just as likely a result of the [[monolithic culture|culture of militarism]] that has become dominant in Klingon society.

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Klingons set the standard for having a [[Bumpy forehead alien|bumpy forehead]] in Star Trek.<ref>''[[Star Trek: The Motion Picture]]''</ref>

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Klingons set the standard for having a [[Bumpy forehead alien|bumpy forehead]] in Star Trek.<ref>''[[Star Trek: The Motion Picture]]''</ref>. From 2154 to the Mid 23rd century, Klingons have lacked the distinctive forhead ridges due to genetic engineering.